Certain engine fluid supply systems include a fluid filtration system designed to separate water from the fluid. An example of this type of engine fluid supply system is a fuel filter assembly that includes a filter housing and a water separating fuel filter element disposed therein. The fluid filtration system may also include a water sensor that extends through the filter housing into the interior thereof to detect if a certain amount of water has been collected in the filter housing. If enough water collects in the filter housing, a signal is sent to the user indicating that the water should be purged from the filter housing by, for example, opening a drain valve. The connection between the water sensor and the filter housing must be watertight to prevent water and fuel leakage. There is a constant need for improving the effectiveness of the retention of a water sensor to the filter housing.